bug#52685: 29.0.50; Horizontal scrolling doesn't work when compiled with pgtk

[Andrey Listopadov <andreyorst@gmail.com>]

On Wed, Dec 22, 2021 at 4:09 AM Po Lu <luangruo@yahoo.com> wrote:
>
> Po Lu <luangruo@yahoo.com> writes:
>
> > Andrey Listopadov <andreyorst@gmail.com> writes:
> >
> >> When `pixel-scroll-precision-mode' is disabled everything works fine.
> >> When compiled without `--with-pgtk' but with `--with-xinput2'
> >> `pixel-scroll-precision-mode' works as expected.
> >
> > Thanks, I will look into this now.
>
> Please try the following patch to see if it resolves your problem.
> Thanks.
>
> diff --git a/src/pgtkterm.c b/src/pgtkterm.c
> index bd61c65edd..bea2650584 100644
> --- a/src/pgtkterm.c
> +++ b/src/pgtkterm.c
> @@ -6133,78 +6133,64 @@ scroll_event (GtkWidget * widget, GdkEvent * event, gpointer * user_data)
>      }
>    else if (gdk_event_get_scroll_deltas (event, &delta_x, &delta_y))
>      {
> -      dpyinfo->scroll.acc_x += delta_x;
> -      dpyinfo->scroll.acc_y += delta_y;
> -      if (dpyinfo->scroll.acc_y >= dpyinfo->scroll.y_per_line
> -         || !mwheel_coalesce_scroll_events)
> +      if (!mwheel_coalesce_scroll_events)
>         {
> -         int nlines = dpyinfo->scroll.acc_y / dpyinfo->scroll.y_per_line;
> -         inev.ie.kind = WHEEL_EVENT;
> -         inev.ie.modifiers |= down_modifier;
> -         inev.ie.arg = list3 (make_fixnum (nlines),
> -                              make_float (-dpyinfo->scroll.acc_x * 100),
> -                              make_float (-dpyinfo->scroll.acc_y * 100));
> -         if (!mwheel_coalesce_scroll_events)
> -           {
> -             dpyinfo->scroll.acc_y = 0;
> -             dpyinfo->scroll.acc_x = 0;
> -           }
> -         else
> +         inev.ie.kind = ((fabs (delta_x) > fabs (delta_y))
> +                         ? HORIZ_WHEEL_EVENT
> +                         : WHEEL_EVENT);
> +         inev.ie.modifiers = (inev.ie.kind == HORIZ_WHEEL_EVENT
> +                              ? (delta_x >= 0 ? down_modifier : up_modifier)
> +                              : (delta_y >= 0 ? down_modifier : up_modifier));
> +         inev.ie.arg = list3 (Qnil, make_float (delta_x),
> +                              make_float (delta_y));
> +       }
> +      else
> +       {
> +         dpyinfo->scroll.acc_x += delta_x;
> +         dpyinfo->scroll.acc_y += delta_y;
> +         if (dpyinfo->scroll.acc_y >= dpyinfo->scroll.y_per_line)
>             {
> +             int nlines = dpyinfo->scroll.acc_y / dpyinfo->scroll.y_per_line;
> +             inev.ie.kind = WHEEL_EVENT;
> +             inev.ie.modifiers |= down_modifier;
> +             inev.ie.arg = list3 (make_fixnum (nlines),
> +                                  make_float (-dpyinfo->scroll.acc_x * 100),
> +                                  make_float (-dpyinfo->scroll.acc_y * 100));
>               dpyinfo->scroll.acc_y -= dpyinfo->scroll.y_per_line * nlines;
>             }
> -       }
> -      else if (dpyinfo->scroll.acc_y <= -dpyinfo->scroll.y_per_line
> -              || !mwheel_coalesce_scroll_events)
> -       {
> -         int nlines = -dpyinfo->scroll.acc_y / dpyinfo->scroll.y_per_line;
> -         inev.ie.kind = WHEEL_EVENT;
> -         inev.ie.modifiers |= up_modifier;
> -         inev.ie.arg = list3 (make_fixnum (nlines),
> -                              make_float (-dpyinfo->scroll.acc_x * 100),
> -                              make_float (-dpyinfo->scroll.acc_y * 100));
> -
> -         if (!mwheel_coalesce_scroll_events)
> +         else if (dpyinfo->scroll.acc_y <= -dpyinfo->scroll.y_per_line)
>             {
> -             dpyinfo->scroll.acc_y = 0;
> -             dpyinfo->scroll.acc_x = 0;
> +             int nlines = -dpyinfo->scroll.acc_y / dpyinfo->scroll.y_per_line;
> +             inev.ie.kind = WHEEL_EVENT;
> +             inev.ie.modifiers |= up_modifier;
> +             inev.ie.arg = list3 (make_fixnum (nlines),
> +                                  make_float (-dpyinfo->scroll.acc_x * 100),
> +                                  make_float (-dpyinfo->scroll.acc_y * 100));
> +
> +             dpyinfo->scroll.acc_y -= -dpyinfo->scroll.y_per_line * nlines;
>             }
> -         else
> -           dpyinfo->scroll.acc_y -= -dpyinfo->scroll.y_per_line * nlines;
> -       }
> -      else if (dpyinfo->scroll.acc_x >= dpyinfo->scroll.x_per_char
> -              || !mwheel_coalesce_scroll_events)
> -       {
> -         int nchars = dpyinfo->scroll.acc_x / dpyinfo->scroll.x_per_char;
> -         inev.ie.kind = HORIZ_WHEEL_EVENT;
> -         inev.ie.modifiers |= up_modifier;
> -         inev.ie.arg = list3 (make_fixnum (nchars),
> -                              make_float (-dpyinfo->scroll.acc_x * 100),
> -                              make_float (-dpyinfo->scroll.acc_y * 100));
> -
> -         if (mwheel_coalesce_scroll_events)
> -           dpyinfo->scroll.acc_x -= dpyinfo->scroll.x_per_char * nchars;
> -         else
> +         else if (dpyinfo->scroll.acc_x >= dpyinfo->scroll.x_per_char
> +                  || !mwheel_coalesce_scroll_events)
>             {
> -             dpyinfo->scroll.acc_x = 0;
> -             dpyinfo->scroll.acc_y = 0;
> +             int nchars = dpyinfo->scroll.acc_x / dpyinfo->scroll.x_per_char;
> +             inev.ie.kind = HORIZ_WHEEL_EVENT;
> +             inev.ie.modifiers |= up_modifier;
> +             inev.ie.arg = list3 (make_fixnum (nchars),
> +                                  make_float (-dpyinfo->scroll.acc_x * 100),
> +                                  make_float (-dpyinfo->scroll.acc_y * 100));
> +
> +             dpyinfo->scroll.acc_x -= dpyinfo->scroll.x_per_char * nchars;
>             }
> -       }
> -      else if (dpyinfo->scroll.acc_x <= -dpyinfo->scroll.x_per_char)
> -       {
> -         int nchars = -dpyinfo->scroll.acc_x / dpyinfo->scroll.x_per_char;
> -         inev.ie.kind = HORIZ_WHEEL_EVENT;
> -         inev.ie.modifiers |= down_modifier;
> -         inev.ie.arg = list3 (make_fixnum (nchars),
> -                              make_float (-dpyinfo->scroll.acc_x * 100),
> -                              make_float (-dpyinfo->scroll.acc_y * 100));
> -
> -         if (mwheel_coalesce_scroll_events)
> -           dpyinfo->scroll.acc_x -= -dpyinfo->scroll.x_per_char * nchars;
> -         else
> +         else if (dpyinfo->scroll.acc_x <= -dpyinfo->scroll.x_per_char)
>             {
> -             dpyinfo->scroll.acc_x = 0;
> -             dpyinfo->scroll.acc_y = 0;
> +             int nchars = -dpyinfo->scroll.acc_x / dpyinfo->scroll.x_per_char;
> +             inev.ie.kind = HORIZ_WHEEL_EVENT;
> +             inev.ie.modifiers |= down_modifier;
> +             inev.ie.arg = list3 (make_fixnum (nchars),
> +                                  make_float (-dpyinfo->scroll.acc_x * 100),
> +                                  make_float (-dpyinfo->scroll.acc_y * 100));
> +
> +             dpyinfo->scroll.acc_x -= -dpyinfo->scroll.x_per_char * nchars;
>             }
>         }
>      }

The patch doesn't apply.

-- 
Andrey Listopadov